a) Số đó là :
60 x 100 : 30 = 200
Đ/S : 200
b) Số đó là :
85 x 100 : 25 = 340
Đ/S : 340
c) Số đó là :
240 x 100 : 12 = 2000
Đ/S : 2000
$a)$
$30\%$ của số đó là 60
$\to$ Số cần tìm là: $\dfrac{60}{30\%}=200$
$25\%$ của số đó là 85
$\to$ Số cần tìm là $\dfrac{85}{25\%}=340$$12\%$ của số đó là 240
$\to$ Số cần tìm là $\dfrac{240}{12\%}=2000$
giup mk bai nay nha , onee -chan
Bài 36: Thực hành: QUAN SÁT CẤU TẠO TRONG CỦA ẾCH ĐỒNG TRÊN BÀN MỔ - Quan sát hình 36.2, cho biết lớp da của ếch đồng có đặc điểm gì? Đặc điểm đó có ý nghĩa gì đối với đời sống của ếch đồng. - Nghiên cứu thông tin ở bảng trang 118 sách giáo khoa, cho biết: + Ếch đồng hô hấp nhờ những cơ quan nào? + Ếch đồng có mấy vòng tuần hoàn? Tim có mấy ngăn? Máu đi nuôi cơ thể thuộc loại máu nào? + Em hiểu như thế nào được gọi là “máu pha”?
1. The 23 rd Sea games____________ in the Philippines. a. will hold b. will held c. would be held d. is held 2. She asked me if I _________pop music a. like b. to like c. will like d. liked 3. I ______it 5 years ago a. have seen b. saw c. was seeing d. am seeing. 4. It's very kind ________you to help me. a. for b. at c. off d. of 5. Would you mind ________I smoked here. a. When b. that c. if d. for 6. The old lamp ________in China is 5 dollars a. to be making b. making c. mode d. make 7. Millions of Chirsmas card _______every year. a. were sent b. are sent c. send d. is sending. 8. I don't know how _________the game a. playing b. to play c. player d. can I play
Câu 2: Có nhiều lúc, em gõ thêm văn bản vào giữa nội dung đã có, xảy ra tình trạng các kí tự gõ vào xóa mất các kí tự đã có ( giống như nó chồng lên vậy ). Em hãy giải thích nguyên nhân và nêu cách khắc phục. Câu 3: Trong lúc làm việc với Word, không may chuột bị lỗi ( không sử dụng được ), em muốn lưu tệp văn bản đang soạn thảo ( tệp văn bản này đã lưu một lần ) và kết thúc phiên làm việc với Word. Trong trường hợp này em thực hiện như thế nào ?
38. The phone ___________________ suddenly while Jane was doing the housework. A. rang B. was ringing C. had rung D. is ringing 39. Sarah has got an exam soon, so she ___________________ very hard at the moment. A. works B. was working C. worked D. is working 40. Rosemary ___________________ to agree with us now. A. is appearing B. appear C. appeared D. appears 41. Look! That man ___________________ your bike! A. is stealing B. stealing C. steals D. stolen 42. Bettie usually ___________________ television in the evening. A. has watched B. watching C. watches D. watch 43. It ______________ quite often in Britain during the winter. A. is snowing B. snows C. snowed D. was snowing 44. I ___________________ Mai for five years. I wonder where she is now. A. don’t see B. hadn’t seen C. haven’t seen D. didn’t see 45. Water ___________________ at 100 degrees Celsius. A. is boiling B. boiling C. boils D. boil 46. Eric ___________________ a flat yet, so he’s still living with his parents. A. didn’t find B. is finding C. hasn’t found D. found 47. We ___________________ any interesting films lately. A. didn’t see B. haven’t seen C. saw D. have seen 48. She looked into her bag but the money ___________________ ! A. was going B. has gone C. had gone D. went 49. It was midnight. Outside it ________________ very hard. A. rains B. is raining C. rained D. was raining 50. Up to now, the pollution problems ________________ yet. A. haven’t solved B. are not solving C. hadn’t solved D. will not have solved
1)Rút gọn biểu thức: a) (x–4)(x–2) –(x–1)(x–3) b) (x+3)(x²–3x+9)–x(x ²–3) c) (x+3) ³(x–1)(x ²+x+1) 2)Chứng minhgiá trị biểu thức sau đây không phụ thuộc vào giá trị của biến. A=(x+2)(x ²–2x+4)–x ²(x–2) –2x ² 3) Chứng tỏ rằng x ²+6x+10 > 0 với mọi x
8. Mr. Harry ______ in the army from 1980 to 1985 A. had served B. has served C. is serving D. served 9. How____ since we____ school? A. are you/ left B. will you be / left C. have you been/ left D. have you been/ had left 10. Who ______ when I came ? A. were you talking to B. are you talking to C. you are talking to D. you were talking to 11. I _____ in the waiting room when I heard someone_____ me. A. am sitting/ to call B. was sitting/ call C. am sitting/ called D. have sat / called 12. My son was sleeping when I ______ home. A. went B. has gone C. had gone D. would go 13. Yesterday when I _____ at the station, the train _______ for 15 minutes. A. arrived/ had left B. arrives/ has left C. arrived/ left D. had arrived/ left 14. When we _____ there, people ______ calmly. A. got/ are waiting B. got/ were waiting C. got/ waited D. get/ wait 15. While I __________ in the street, I saw my old friend. A. was walking B. am walking C. walk D. walked 16. “When did you come here?” “I ____ here since last Sunday.” A. have been B. had been C. was D. am 17. People ____ English and French in Canada. A. speak B. have spoken C. had spoken D. are speaking 18. While I was going to school yesterday, I ____ him. A. meet B. met C. will meet D. am meeting 19. They were in a hurry because they thought that the class _____. A. had already begun B. have already begun C. was begun D. will begin 20. We _____ in this house for ten years. A. are living B. were living C. had lived D. have lived 13. ___________________ to rain before you woke up this morning? A. Did it begin B. Had it begun C. Has it begun D. Began 21. Pasteur ___________________ in the 19 th century. A. was living B. lived C. had lived D. has lived 22. While she ___________________ the room, she broke the vase. A. was cleaning B. has cleaned C. had cleaned D. cleaned 23. By the time we got to the market, all the shops ___________________ . A. have closed B. were closing C. had closed D. closed 24. John ___________________ his first piece of music when he was ten years old. A. wrote B. was writing C. writes D. written 25. My daughter saw an elephant this morning, but she ___________________ one before. A. had never seen B. has never seen C. never sees D. never had seen 26. While Mai ___________________ the meal, her brother ___________________ the house. A. cooked / clean B. cooked/was cleaning C. was cooking/cleaned D. was cooking / was cleaning 27. The manager ___________________ a letter when I interrupted him. A. has read B. reads C. was reading D. read 28. The film ___________________ when we arrived at the cinema. A. has begun B. begun C. had begun D. begins 29. When I ___________________ home, my parents ___________________ to work. A. got / went B. was getting / went C. got / had gone D. was getting / had gone 30. Ann ___________________ very hard at the moment. A. has studied B. studied C. is studying D. studies 31.The accident ___________________ when we were on the way to HN. A. had occurred B. occurring C. occurred D. occur 32. They ________________ small cups of coffee after they __________________ dinner. A. had drunk / finished B. drank / finished C. drank / had finished D. were drinking / finished 33. The sun _______________ before I _________________ ready to go. A. set / had been B. had set / was C. was setting / was D. was setting / had been 34. In Hamlet, the opening scene ___________________ place at night. A. was taking B. takes C. is taking D. has taken 35. You ____________ your new hat when I _______________ you yesterday. A. wore / had met B. wore / was meeting C. were wearing / met D. were wearing / had met 36. Andrew _______________ the test before so he _____________ it very easy. A. did / had found B. was doing / found C. had done / found D. did / was finding
lmạy chúa cứu Choose the sentence which has a similar meaning to the first one. Question 25. There is little hope that Craig will be able to find a job. A: Craig hopes that he won’t have to find work for himself. B: Craig has given up hope of finding employment. C: It is not very likely that Craig’s search for employment will be successful. D: Craig hopes that it will only take a little time for him to get work.
trung binh cong cua ba so la so be nhat co ba chu so . tim so thu ba , biet tong cua so thu nhat va so thu hai so lon nhat co hai chu so
Tìm giá trị của m (mZ), để hệ phương trình sau: 2 1 xmy mxy có nghiệm x > 0; y < 0
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